JPH05314719A - Hub for cassette tape - Google Patents

Abstract

PURPOSE:To provide a hub for cassette tape capable of preventing the attachment/detachment for a hub driving reel from becoming the unable state due to a contraction of the inner diameter by the winding pressure of a magnetic tape. CONSTITUTION:The hub 1 for the cassette tape is constituted of an inner ring body 3 provided with driving lugs 2...2 engaging with the hub driving reel of a tape recorder on the inner peripheral surface and foamed resin layers 4 provided on the outer perpheral surface of the inner ring body 3, then the inner diameter of the inner ring body 3 is prevented from the contraction by making the foamed resin layers 4 to be contracted. Also, noise and vibration generated at the time of rotation are absorbed by the foamed resin layers 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hub for feeding and winding a tape recording medium (hereinafter referred to as a magnetic tape) in a cassette tape.

[0002]

2. Description of the Related Art A hub of a cassette tape, for example, a hub of a compact cassette tape, is made of non-foaming synthetic resin such as POM (polyacetal) or PP (polyprolylen).
As shown in FIGS. 7 to 8, it is formed in a ring shape. On the inner peripheral surface of the hub 101, a hub drive reel 202 of a tape drive (tape recorder) 201,
Drive ribs (claws) 204 ... 204 provided on the outer peripheral surface of 203
102 are provided to engage with, and a tape clamp groove 103 is provided on the outer peripheral surface, and an end portion of the magnetic tape 105 is locked by a clamper 104 fitted in the clamp groove 103, The magnetic tape 105 is wound around the outer peripheral surface to feed or wind the magnetic tape 105.

[0003]

The conventional hub 101 has the following problems because it is made of non-foaming synthetic resin such as POM and PP.

(1) When the cassette tape is stored at a high temperature for a long time, the rigidity of the hub 101 is reduced, and the hub is pressed by the winding pressure (tightening force) of the magnetic tape 105 being wound. 101 shrinks, and as shown in FIGS. 8 and 9, the inner diameter A of the hub 101 changes so that the hub drive reel 202,
The diameter B of the drive rib 204 of 203 is smaller than the diameter B of the drive claw 102 of the hub 101, or the diameter C of the drive claw 102 of the hub 101 is smaller than the diameter D of the hub drive reels 202 and 203. , 203 will not fit. In addition, the hub 101 is the hub drive reel 202,
When the hub 101 contracts while attached to 203,
In some cases, the hub 101 cannot be removed from the hub drive reels 202 and 203, and the cassette tape cannot be removed from the tape drive.

(2) The hub 101 generates vibration and noise during high speed rotation.

An object of the present invention is to solve the above conventional problems and to provide a hub of a cassette tape which does not change its inner diameter due to the winding pressure of the magnetic tape and has a vibration and noise absorbing performance. It is a thing.

[0007]

In a hub of a cassette tape according to the present invention, an inner ring member is provided on an inner peripheral surface of a drive claw that engages with a hub driving reel on a drive side, and an inner ring member is provided on an outer peripheral surface of the inner ring member. A hub is formed of the foamed resin layer that is more elastic than the inner ring body, and a magnetic tape is wound around the outer peripheral surface of the foamed resin layer.

[0008]

The winding pressure of the magnetic tape is applied to the foamed resin layer to shrink the foamed resin layer and prevent the inner race from shrinking.

[0009]

The hub of the cassette tape of the present invention will now be described with reference to the drawings.

1 to 3 show a first embodiment, a hub 1 is an inner ring body 3 provided with drive pawls 2 ... 2 which engage with a drive rib of a hub drive reel on the drive side, and an inner ring body 3. The foamed resin layer 4 is provided on the outer peripheral surface of the inner race 3, and the magnetic tape 5 is wound around the outer peripheral surface of the foamed resin layer 4.

The inner race 3 is made of POM (non-foamed) in consideration of mechanical strength (rigidity) and the like.

Further, the foamed resin layer 4 is rich in lubricity and is capable of blending a foaming agent with sliding property PP and sliding property HI-P.
It is made of synthetic resin such as S and POM.

The foamed resin layer 4 is formed as follows.

That is, when the resin temperature of PP blended with a foaming agent is molded without the foaming agent (hereinafter 100% P
While the temperature of the mold is set higher than the resin temperature of P), the mold temperature is set slightly lower than the case of molding 100% PP.

Then, if the above PP is injected into the mold,
PP flows along the inner wall of the mold, and the portion contacting the inner wall of the mold is solidified immediately without sufficient foaming due to the low temperature of the mold.

On the other hand, the inner PP is solidified while slowly foaming without being rapidly cooled by the mold. In this way, the foamed resin layer 4 having a high foaming ratio inside and a low foaming ratio at the surface portion and having a non-foaming surface layer called a skin layer is formed.

In FIG. 1, 6 is a tape clamp groove provided on the surface of the foamed resin layer 4, and the clamp groove 6
One end of the magnetic tape 5 is locked to the hub 1 by the clamp 7 fitted to the magnetic tape 5, and the magnetic tape 5 is wound around the outer peripheral surface of the hub 1.

The hub 1 of the first embodiment is constructed as described above, and the winding pressure of the magnetic tape 5 is applied to the foamed resin layer portion 4,
The foamed resin layer 4 shrinks to absorb the winding pressure, and the winding pressure prevents the inner race 3 from shrinking.

4 to 6 show a second embodiment.

In this embodiment, an outer race 11 is provided on the outer peripheral surface of the foamed resin layer 4, and the foamed resin layer 4 is sandwiched between the inner race 3 and the outer race 11.

The outer ring body 11 is made of the same material as the inner ring body 3 and has a function of reinforcing the outer peripheral surface side of the foamed resin layer 4.

Since the other structure is the same as that of the first embodiment, the same components are designated by the same reference numerals and the duplicate description will be omitted.

[0023]

The hub of the cassette tape of the present invention has the following effects.

(1) Since the foaming resin layer absorbs the winding pressure of the magnetic tape and the foaming resin layer is prevented from contracting and the winding pressure being applied to the inner ring body side, the cassette tape is stored at a high temperature. Then, even if the strength (rigidity) of the inner ring decreases,
It prevents the inner diameter of the inner ring body, that is, the inner diameter of the hub from shrinking, making it impossible to attach the hub to the hub drive reel or to remove the hub from the hub drive reel due to the shrinkage of the hub inner diameter It can be surely prevented from becoming.

(2) The foamed resin layer can absorb noise and vibration during high-speed circuit operation of the hub, and can suppress the generation of modulation noise caused by these vibrations.

[Brief description of drawings]

FIG. 1 is a plan view of a first embodiment.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a cross-sectional view showing a state in which a foamed resin layer is contracted.

FIG. 4 is a plan view of the second embodiment.

5 is a cross-sectional view taken along the line BB of FIG.

FIG. 6 is a cross-sectional view of the foamed resin layer in a contracted state.

FIG. 7 is a perspective view of a cassette tape.

FIG. 8 is a perspective view of a conventional hub.

FIG. 9 is a cross-sectional view showing the relationship between the hub and the hub drive reel.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Hub 2 ... Driving claw 3 ... Inner ring body 4 ... Foam resin layer 5 ... Magnetic tape 11 ... Outer ring body

Claims (3)

[Claims] 1. A foamed resin comprising: an inner ring body having a drive claw engaged with a hub drive reel on the drive side provided on an inner peripheral surface thereof; and a foamed resin layer provided on an outer peripheral surface of the inner ring body. A hub for a cassette tape, characterized in that a tape-shaped recording medium is wound around the outer peripheral surface of the layer. 2. The cassette according to claim 1, wherein an outer ring body made of non-foamed resin is further provided on the outer peripheral surface of the foamed resin layer, and the tape-shaped recording medium is wound around the outer peripheral surface of the outer ring body. Tape hub. 3. The hub of the cassette tape according to claim 1, wherein the inner ring is made of polyacetal.